Future directions and technology requirements of wireless communications

The third generation mobile services using W-CDMA first began in Japan. Further research on next mobile systems has already been started. The paper briefly describes the history of cellular systems and then introduces a technical outline of new generation systems. A broadband wireless communication requires a wide frequency bandwidth, huge delay spread tolerance, big transmission power and subscriber capacity. In order to obtain a smart solution, further digital processing approaches with the most advanced CMOS technology will be a key issue as well as the low-distortion and high-frequency power devices.